Question

C# 替换字符

有一个字符，比如：string a = "abcdefghijklmn";现在要将里面的字符进行替换，将a替换成1，其余字符都替换成0，这个怎么写？？菜鸟跪求~~

Answer 1

string a = "abcdefghijklmn";
a = a.Replace("a","1");
string result = "";
string otherChar = a.ToCharArray();
foreach(char text in otherChar)
{
    if(text != "1") { result += "0"; }
    else{ result += "1"; }
}

Answer 2

string a = "abcdefghijkalmn";
//非a替换成0，忽略大小写
a= System.Text.RegularExpressions.Regex.Replace(a,"[^a]","0",System.Text.RegularExpressions.RegexOptions.IgnoreCase);
//a替换成1，忽略大小写
a = System.Text.RegularExpressions.Regex.Replace(a, "a", "1", System.Text.RegularExpressions.RegexOptions.IgnoreCase); ;

Console.WriteLine(a);

Answer 3

string str = "aaabbbcccsdd";
char[] cc = str.ToCharArray();
StringBuilder sb = new StringBuilder();
foreach (char c in cc)
{
if (c == 'a')
{
sb.Append("1");
}
else
{
sb.Append("0");
}
}
Console.WriteLine(sb.ToString());
Console.ReadKey();